Radiation-Crosslinked Cellulose Hydrogel for Sterile Injection
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Solution Overview
Problem
The challenge lies in creating a sterile and injectable hydrogel based on water-soluble polymers derived from cellulose, which is sensitive to radiation, requiring precise adjustments in polymer concentration and radiation dose to achieve crosslinking while maintaining sterility, especially for biomedical applications where 'paste-like conditions' are critical.
Innovation Solution
A method involving an aqueous solution of a cellulose-derived polymer combined with another water-soluble polymer, exposed to β or γ radiation within specific concentration and dose ranges to achieve crosslinking and sterilization, forming a homogeneous injectable hydrogel, suitable for biomedical uses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiation dose is increased to achieve crosslinking and sterilization, then gel formation and sterility are improved, but polymer degradation increases
Solution Approach 1:
The patent optimizes the radiation dose parameter to a specific range (5-50 kGy, preferably 10-30 kGy) to achieve the desired balance between crosslinking/sterilization and degradation. This parameter optimization resolves the contradiction by finding the optimal point where beneficial effects (gel formation, sterility) are maximized while harmful effects (degradation) are minimized.
Solution Approach 2:
The patent uses composite polymer systems combining cellulose-derived polymers with other water-soluble polymers (proteins, polysaccharides, synthetic polymers). This composite approach enhances radiostability and controls the balance between crosslinking and degradation, as different polymer components respond differently to radiation, allowing tailored gel formation with minimized degradation.
2Volume of moving object
If polymer concentration is increased to achieve sufficient gel volume, then gel volume is improved, but viscosity increases making injection difficult
Solution Approach 1:
The patent exploits the phase transition of the polymer solution from liquid to gel upon radiation exposure. The solution is formulated at a concentration that remains injectable in liquid form, then transitions to a gel with sufficient volume after irradiation. This phase transition resolves the contradiction by allowing low viscosity during injection and high volume after gelation.
Solution Approach 2:
The patent creates a dynamic system where the physical state and properties of the hydrogel change over time and under different conditions (temperature, radiation dose, polymer concentration). The gel can be administered in a low-viscosity state and then transformed into a higher-volume gel structure, providing operational flexibility that resolves the volume-injection contradiction.
3Object-affected harmful factors
If radiation dose is increased to ensure complete sterilization, then sterility is improved, but uncontrolled modifications and degradation increase
Solution Approach 1:
The patent employs composite polymer formulations that include radiostabilizing components and polymers with different radiation sensitivities. This composite structure provides radioprotection, allowing effective sterilization at lower doses while minimizing uncontrolled modifications and degradation through the synergistic effects of different polymer components.
Solution Approach 2:
The patent optimizes multiple parameters including radiation dose (5-50 kGy), polymer concentration (0.5-10%), and polymer composition ratios to achieve sterilization while controlling modifications. This multi-parameter optimization resolves the contradiction by finding the optimal treatment window where sterilization is effective but harmful modifications are minimized.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method efficiently produces a sterile, injectable hydrogel with controlled properties, enhancing biocompatibility and mechanical properties, suitable for various biomedical applications, including tissue engineering and bone substitutes, while avoiding uncontrolled modifications and degradation.
Implementation Method 1
chemical gels (real, permanent gels), in which covalent bonds connect the chains
Implementation Method 2
Crosslinking of the polymers and sterility of the material are obtained simultaneously by means of β or γ irradiation
Data Source
AI summary
The invention relates to a method for preparing a cross-linked sterile and homogeneous hydrogel for injection, characterized in that it comprises the following steps: (a) preparing an aqueous solution containing a polymer derived from cellulose and at least one water-soluble polymer, the total polymer content ranging from 0.5 and 5 wt %, preferably from 1 to 4 wt % and more preferably from 1.5 to 3 wt %; (b) optionally adding sold particles; (c) pouring the resulting liquid mixture with the optional solid particles into a vessel and closing dais vessel using a water-tight and gas-tight system; and (d) exposing said vessel containing the liquid and the optional solid particles to a radiation dose of between 5 and 50 kGy, preferably between 20 and 30 kGy, and more preferably of about 25 kGy. The invention also relates to a hydrogel obtained according to the above method and to the use thereof in medical applications.